Metabolic and hemodynamic aspects of peritumoral low-density areas in human brain tumor.

With the use of positron emission tomography, regional cerebral blood flow, oxygen utilization, and glucose utilization were measured in the peritumoral low-density areas on x-ray computed tomographic images in 23 patients with supratentorial brain tumors: 7 meningiomas, 11 malignant gliomas, and 5 metastatic brain tumors. Findings on positron emission tomography in these areas revealed characteristic patterns associated with the types of tumor and the degree of mass effect. It is likely that two different types of pathophysiological states exist in "peritumoral edema": 1) primary ischemia caused by mechanical compression by the tumor mass in meningiomas; and 2) primary metabolic suppression (mainly in oxygen metabolism) in malignant brain tumors.